update_engine: guarded 740efad for only android

740efad439e57e71d8d459c366edea3a90b19576: Reboot even if a system update is not available.

The above patch removes a part of code in ChromeOS, but the Android still needs
it. That patch has been reverted in AOSP.

This CL guards that piece of code to be built on non-chromeos builds so there
would be no need for reverting it again in android when merging back and forth.

BUG=chromium:815356
TEST=unittests

Change-Id: Ieb8f246d9dba0bd2b7ee7ecc4e3b7823249b3599
Reviewed-on: https://chromium-review.googlesource.com/965265
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Sen Jiang <senj@chromium.org>
diff --git a/update_attempter.cc b/update_attempter.cc
index 9cef154..b289b1e 100644
--- a/update_attempter.cc
+++ b/update_attempter.cc
@@ -813,11 +813,13 @@
 }
 
 bool UpdateAttempter::RebootIfNeeded() {
+#ifdef __ANDROID__
   if (status_ != UpdateStatus::UPDATED_NEED_REBOOT) {
     LOG(INFO) << "Reboot requested, but status is "
               << UpdateStatusToString(status_) << ", so not rebooting.";
     return false;
   }
+#endif  // __ANDROID__
 
   if (system_state_->power_manager()->RequestReboot())
     return true;